The best thing to keep your retwists held in place is to sleep with your head covered. Really! Even product with a light hold, like the natural “gel” from inside aloe vera plants will give me a nice, lasting retwist if I’m diligent about sleeping with my hair wrapped up.
But if you want a nice hold, I hear homemade flaxseed gel works well. Try to avoid things like honey or waxes.
Other than this, I’ll have to leave it up to our followers to help, because I don’t use commercial gels on my hair.
Followers: What washable gel has a nice, strong hold for retwisting locs?