If you rinse the outer sponges often enough, there shouldn't be any need to. You probably only need to rinse out your biomedia once or twice a year, depending on your stocking level.
My 3 are on Oscar tanks (2 Oscars per 125 g tank). We've got well water (no chlorine) I use a strong jet nozzle every 2 wks and rinse the big sponges and the bio-media on the deck. I don't like all the gunk sitting in there building up & increasing nitrates. I can't imagine going 2-3 months, I didn't realize others waited that long. I'm old and set in my ways, so every 2 wks is what it'll stay Ammon/nitrites are always zero and the tank bottoms are always spotless. Works for me.