Question about floor drains (Amman)

I have floor drains in my kitchen, bathrooms and laundry room (as I'm sure you do too). The ones in the bathrooms and laundry seem to smell bad; I noticed they contain standing water. Is there anything I can buy to sanitize them? I've just tried boiling water and was thinking of vinegar but maybe there's a commercial product you're supposed to use.

Don't have these back home in North America so I'm at a loss.