1. Don't include the wildcard in the talkgroups on that system - that will exclude talkgroups you don't specifically program.
2. Don't program any talkgroups you don't want to hear.
Going thru and locking out groups you don't want to hear suggests that you have something pre-programmed or have the wildcard in the mix. If it's pre-programmed - you can re-program or just lock out the TGs as you said.
(To lock them out permanently push Funt-Lockout when the TG is up.)