I like to wait a day if possible. Ideally, I do two applications, one (somewhat aggressive) the first day and the second (very gentle) the next, and then I'll apply my LSP without much of a wait (maybe an hour or so).
It's my understanding that the SRP does in fact "cure" in some way that needs a bit of time. I've used it with zero wait, but I don't *think* that's optimal.