Don't rinse it in tank water that is in the tank. Rinse it in the tank water you remove from the tank during water changes (i.e. in the bucket or whatever you use before you dump it out). If you use a python or something like that, then rinse it out in the water as it flows out of the python into the sink. Using untreated tapwater will kill the bacteria because of any added chlorine or chloramines in the water (unless you are on a well, go for it in that case probably).