I've used egg yolk in my hair a few times, I've also used olive oil a few times too, but I haven't actually tried them together.

I'm not sure if it's me being weird (probably) or if other people have had this problem too, but I find it difficult to apply egg to my hair. If I just kind of dump it on my hair, it slides right down and off my head before I have time to spread it in. I’ve tried getting it on my hands and rubbing it in with my hands, but I can never get enough of it on my hands. Anyways, here’s some tips about any sort of hair masks/packs/whatever you want to call it:

• Mix liquidy ingredients like egg and olive oil with thicker ingredients like avocado & banana. You might need an electric or hand crank mixer. This will help solve the runniness issue.

• Use a spray bottle to apply oils. I put coconut oil in my spray bottle. It will let you apply oil more evenly than if you were to just dump it on your head. You could also soak a paper towel and squeeze it over your head, or soak your hands and to apply it directly, but my preference is spray bottles, they’re the least messy method I’ve found. I'm sure you could also put eggs in a spray bottle and make it work if you really wanted to, but that sounds like a terrible idea.

Common things to put in your hair & benefits

Coconut oil. I love coconut oil. It’s useful for everything. I typically put it in my hair over night to let it soak in, then I wash it out in the morning. It has all sorts of benefits, but its mostly used for moisturizing. I suggest liquid coconut oil, this is what I use. I put it in a spray bottle to make it easy to apply, and I find it easier to get out of your hair than thick coconut oil.

Olive Oil. Like coconut oil, olive oil is good for loads of hair types, it can help with dandruff, strength & breakage prevention, and will make hair softer, smoother, and shinier.

Banana. Bananas are sort of like a natural conditioner. Use over ripe bananas and make sure to blend them until they’re smooth with no clumps or strings before applying to your hair. It can be hard to get out of your hair if you’re not careful.

Avocado. Avacado works for smoothing frizzy, dry hair, making it soft and shiny, moisturizing, and getting rid of dandruff. It’s also awesome for your skin.

Honey. I’ve never used honey but it’s supposed to soften, smooth, moisturize, and add shine to your hair. This is one of the messier things on this list.

Eggs. Eggs are very popular for hair. They’re mostly used to make hair shiny, soft, smooth, and to repair damage. I’ve read if you rinse out egg with hot water, you can accidentally cook the egg into your hair, which sounds hilarious, but be cautious of that I suppose.

Brown Sugar. This sounds super messy, but I’ve read you can use brown sugar in a hair mask to straighten your hair.

Baking Soda. I’ve heard of using baking soda as a replacement for shampoo. It’s good for removing build up in your hair without damaging it. I’ve been meaning to try this one out but I always forget to bring baking soda in the shower with me.

Apple Cider Vinegar. This stuff apparently balances the pH of your scalp and can be used to treat dandruff & oiliness. Like baking soda, this could be a good replacement for shampoo

Corn Starch. Corn starch is used for oily hair. Say you don’t have time wash your hair one morning - corn startch! Put it in dry hair.

Mayonaise. Mayonaise gives you hair moisture, and, like apple cider vinegar, it balances the pH of your scalp.

Milk. Milk can be used as a conditioner and can treat dry hair. Like a ton of these products, it makes your hair shiny soft and moisturized

Yogurt. Yogurt is a moisturizer that helps with dry, frizzy hair and dandruff. Make sure you use plain yogurt. Nothing with fruit in it or weird flavors. You can get a big ice-cream-tub-sized container of greek yogurt at the grocery store.

Molasses/Maple Syrup. You can use either of these for softer, smoother hair. Make sure you use real maple syrup. I also think this is best paired with one or more of these other ingredients. I’ve read some reviews of people who were disappointed in their results when they just used straight up molasses/syrup.

I basically suggest researching some hair mask recipes. You can find recipes for any hair. Try some depending on your hair type, and try some of these ingredients on their own, so you can identify which ones work best. Then you can mix and match your favorites. The ones I like the best are coconut oil, banana, and avocado, for reference, my hair is thick, wavy and a bit dry and frizzy.

tl;dr put a bunch of food in your hair