Maybe it's a silly question, but I wanna be sure 100% before doing that.

I received a few dirty negatives from the lab. In particular you can see in the light that the gelatin surface is a bit hazy with traces from sponge all over and stains along the edges (possibly dried chemicals). Thus, I think to give them a wash again using my b&w reel and tank. May I put wetting agent in the water? Any other idea on cleaning then thoroughly?