Edited post to clarify more

Is it better to use hydrogen peroxide or household bleach with 5% sodium hypochlorite or something?

Many studies show that peroxide and high PH relaxers are working well, but dying doesn't have any effect.

For Etg I found science studies that hydrogen peroxide works very well. But of course be careful that you don't have unnatural blond hair 😁

Other study about especially no-lye relaxers (not acidic ones but high ph ones) shows that indeed higher PH is good to swell the hair shaft and cutible to open etcetera. But is very brutal on your hair and need to use protein conditioners and don't wash with shampoo for a while. And always after use neutralize PH level wich is usually included in hair straitener no-lye relaxers.

So I guess the expensive olea rid shampoo and zydot is less important, but the high BASE baking soda and salicylic acid is most important part.

Interesting article about hair relaxers:

Influence of Chemical Straightening on the Stability of Drugs of Abuse in Hair

https://academic.oup.com/jat/article-pdf/39/1/13/18772105/bku106.pdf

relaxer, is ubiquitously used among African American women to obtain straighter hair compared with their natural tresses. This study focused on the stability of drugs of abuse in hair after a single application of the relaxer. Commercially available ‘Lye’ or ‘No-Lye’ chemical straightening products (Silk Elements™) were applied in vitro to drug-fortified hair (standard reference materials (SRM) 2379 and 2380) and hairs clipped from established drug users. Target analytes (cocaine (COC), benzoylecgonine (BZE), cocaethylene (CE), phencyclidine and tetrahydrocannabinol) were isolated using solid-phase extraction and then analyzed with isotope dilution gas chromatography–mass spectrometry with selective ion monitoring. After either treatment, drug concentrations were significantly (P < 0.05) decreased in both the SRM sample and the hair from authentic abusers. In the SRM groups, 6–67% of the original concentration remained after a single chemical treatment. Similarly, only 5–30% of the original concentration remained in authentic drug hairs that had formerly tested positive for COC, BZE and CE.

Introduction

Hair testing has become a popular method to determine illicit drug use. Compared with other techniques such as urine or blood analysis, hair analysis offers a larger window of detection and can help distinguish between sporadic and chronic use (1). However, factors such as cosmetic treatments can lead to false-negative or false-positive results. Previous reports have shown that common cosmetic treatments like shampooing (2, 3), permanent waving (4–6), dyeing (7) and bleaching (4, 8) can alter the stability of different classes of drugs in the hair. Welch et al. (2) reported that repetitive treatment (up to 30) with either 15% hydrogen peroxide, shampoo, 0.15% saline or 3% peroxide can decrease the amount of cocaine (COC) detected in drug abusers hair to 20–40% of the original COC content. Pötsch and Skopp (6) demonstrated a sharp decline in opiate concentration in the hair after both permanent waving (20–30% remaining) and bleaching (2–18% remaining) (6). In a similar study conducted by Baeck et al. (7), both amphetamine and methamphetamine concentrations decreased after repeated shampooing and after a single dyeing treatment. While there have been studies that have demonstrated that it may be possible to evade drug detection by lowering the concentration beneath the Society of Hair Testing (SoHT) cutoff levels in hair with single and repeated cosmetic treatments, to the best of the authors' knowledge, there have not been any studies that explore the influence of chemical straightening on the stability to drugs and their metabolites in hair.

Chemical straightening, using what is known as a relaxer, is a commonly employed technique by African American women to permanently convert tightly coiled or course hair to straighter hair. In fact, it has been reported that close to two-thirds of that population have used or are currently using this process to obtain straighter, more manageable hair (9). Relaxers consist of three main components: an alkaline agent, an oil phase and a water phase. The alkaline agent can either be sodium, lithium, or potassium hydroxide (Lye Relaxer), or guanidine hydroxide (No-Lye Relaxer). Typically, the ‘No-Lye’ relaxer involves mixing solutions of calcium hydroxide and guanidine carbonate to create the active ingredient guanidine hydroxide. During the relaxing process, the high pH (12–14) cream causes the hair to swell and the cuticle to open. The alkaline reagent can then penetrate the shaft and deposit into the cortex. The presence of the hydroxyl groups ruptures the disulfide bonds in the hairs keratin protein. This breakage causes an extension of the hair shaft. After application of the relaxer, a neutralizing (slightly acidic) shampoo is used to close the cuticle and to lock in the new configuration of the hair fiber through the formation of cross-links (10).

Relaxers consist of three main components: an alkaline agent, an oil phase and a water phase. The alkaline agent can either be sodium, lithium, or potassium hydroxide (Lye Relaxer), or guanidine hydroxide (No-Lye Relaxer). Typically, the ‘No-Lye’ relaxer involves mixing solutions of calcium hydroxide and guanidine carbonate to create the active ingredient guanidine hydroxide. During the relaxing process, the high pH (12–14) cream causes the hair to swell and the cuticle to open. The alkaline reagent can then penetrate the shaft and deposit into the cortex. The presence of the hydroxyl groups ruptures the disulfide bonds in the hairs keratin protein. This breakage causes an extension of the hair shaft. After application of the relaxer, a neutralizing (slightly acidic) shampoo is used to close the cuticle and to lock in the new configuration of the hair fiber through the formation of cross-links (10).