Searching in slack is a dumpster fire due to the nature of a chat room (which all slack is). It is impossible to group bits of useful information together. Once a chat gets going in a room about topic A there is absolutely no way to separate that information from another chat going on in the same room. If the answer is "smaller rooms" then that sort defeats the whole purpose of a chat room.

Sorry to say this, but if you are answering things on slack at home, you are "working" and anchored to your phone.