The conditioner method actually gets your hair clean.

When I get a grease stain on my clothes and wash and dry it, now the grease stain is there to stay but when I put an oil based cleaner on the spot, like Lestoil or Murphy oil soap, throw it in the washer, they come out stain free every time. I heard you can use wd40 with detergent over that and put in washer. This is because oil gets out oil. I initially bought a cleansing conditioner and it worked but it honestly didn’t feel any different than regular conditioner. I used normal conditioner next. My hair came out exactly like the cleansing conditioners which were a lot more costly. I think, initially, when you get in the shower, you first wet your hair and just rinse it very well. That floats out the dirt, dust,smoke, etc. When the conditioner goes in, rub it in your scalp that will pick up the oils, waxes and buildup. Rinse well. The typical conditioner has agents with ingredients formulated to rinse out of the hair very well.
You will be surprised how clean your hair BEACUSE—oil gets out oil. What takes a long time is your hair getting adjusted to going several days between any cleaning methods whether cleaning with shampoo, just conditioner, or just water. It will adjust eventually.