i think generally people say not to use conditioner before your install but i think that depends on your hair type. i think the idea is that you don't want it silky smooth because that can make it harder to control. i think a clarifying shampoo/gentle shampoo the night before would work.
personally, i went "no poo" the weeks before i installed my dreads. my reasoning was that i have very fine hair and i was shampooing it every day and it was STILL getting so oily. i didn't want my scalp and roots to become oily quickly when i had my dreads in. so i wanted to eliminate shampoo in hopes that my scalp would reset itself and get less oily less quickly. i also was having an issue with dandruff and some breaking out under my hair and around my hairline so i wanted to eliminate chemicals and styling products to see if that helped. i'm SO GLAD i decided to go "no poo"!! i kind of followed this article:
http://thehairpin.com/2011/04/how-to-qu ... disgusting my regimen was 1 tbsp baking soda to one cup of water (in a squirt bottle. i used maybe 1/4 of it each shower. and then followed that with a lemon juice/water rinse and washed that out in coldish water. my hair has never felt better or healthier!! since you are installing in a few days this might not be enough time for you if it's something your interested in. but i find going "no poo" to be really compatible with wearing dreads!
however everyone's hair type is different so it can take time to find out what recipes/rinses work well for you.
this livejournal community is also very helpful:
http://no-poo.livejournal.com/
