There are many different scalp complaints, and mild moderate and severe forms which can look quite different, even have different symptoms in different people. If you do not have seborrhoeic dermatitis (greasy dandruff, caused by a yeast) you do not need a medicated shampoo at all, in fact that can worsen other scalp complaints. If it returns please get a formal diagnosis rather than blindly amateur treating.
Many of us use our rinse out conditioner as a leave in conditioner. How much you need depends on your hair, I am porous so needs loads of leave in conditioner.
2a-2c, medium texture, porous/ colour treated. Three years CG, growing out mechanical and chemical damage = breakage and very high porosity. Past armpit length heading for waist.
Treatments: Komaza protein, Komaza Matani, coconut oil with sugar syrup. Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss ultimate volume
Styler: Umberto Giannini jelly, Boots curl creme, Rockin RInglets
Experimenting with: Mega-Tek, Curl Harmony reviver, Elvive Full Restore 5.