If you do this at home, you can do it hours before you plan to wash it - I sleep with it in my hair and wash it out with Loreal Professional Delicate Color Sulfate Free Shampoo the next morning. If you're a no-poo-er, I suggest using the Ouidad Cleansing Oil instead. You can condition your hair as usual, or, for extra awesomeness, follow with an apple cider vinegar rinse use up to half acv to half water, or try using 2 parts water to 1 part acv. Let that site for at least 2 minutes, RINSE WELL. Be SO careful not to get it in your eyes, it burns like a BITCH. It's not harsh on your hair, though - the acidity of the vinegar is actually very gentle on the cuticle helping to close it down as much as possible and ads amazing shine. It works the same way as a conditioner does, but because its ph is more acidic than a traditional water based emulsified conditioner, you get the manageability and detangling benefits without weight of the emulsifying agents. I still suggest adding a leave in conditioner after you scrunch the excess moisture out. Style as usual. I don't suggest using this on freshly colored hair, it can possibly fade the color - especially a demi permanent that doesn't penetrate all the way into the hair.
I've been amazed with the results I've seen since I've been telling people to try it. Only a few people said their hair smelled of vinegar after it dried - if this happens, try reducing the vinegar ratio and even infusing the vinegar with lavender. Most people are using a leave in conditioner which should completely take away any lingering vinegar scent. It's really worth trying it a few times, and even once a week, bi weekly, anything. You can play with the acv to water ratio, when I do it at home, I use 1/3 acv to 1/2 water, because i really like to do it once every other week and that's what seems best for my hair. The more frequently you do it, the lower I'd keep the acv to water ratio.