Baking soda is horrible for skin and hair, even in moderation since the hair prefers pH ~4.5 and skin ~5.5, plus it raises the cuticle so you risk losing much of the protein you just deposited. Don't understand the mayonnaise reference in this context, that is an oil treatment not a protein treatment?

I cleanse hydrolysed protein treatments out without shampoo just conditioner or straight water. Always have to follow with an intensive condition or I have straw like hair, I usually include coconut oil to reduce porosity.
2a-2c, medium texture, porous/ colour treated. Three years CG. Past bra strap length heading for waist.

CO-wash: Inecto coconut/ Elvive Volume Collagen
Treatments: Komaza Care Matani, coconut/ sweet almond/ fractionated coconut oils, Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss Ultimate Volume, various Elvive
Styler: Umberto Giannini jelly, Au Naturale styling gelee
Flour sack towel, pixie diffuse or air dry.
Experimenting with: benign neglect