Sorry, but I can't help you with the white jets - I actually thought Artesian uses grey jets (mine are grey with SS rings).
But as fior the "paste" - where are you adding the dichlor? I typically add it to the tub with all the jets on and haven't had a problem yet. I've read that some people add it to their filter compartment and maybe that's the problem. Also, what's your other chemistry's look like ... maybe it's hard water and the dichlor can't desolve or even calcium buildup.