Yep, just rinse... like Nemo would say... just keep rinsing, just keep rinsing, just keep rinsing, rinsing, rinsing.... (yeah, I watched Finding Nemo with my 2 year old last night.... sigh).
FWIW, I rinse my filters out in the bath tub using regular old tap water. Hasn't caused me any problems. While it's best to rinse them in tank water, sometimes, that's a little more difficult considering the method of water changes.
"What, exactly, is the internet? Basically it is a global network exchanging digitized data in such a way that any computer, anywhere, that is equipped with a device called a 'modem', can make a noise like a duck choking on a kazoo." - Dave Barry