Hi,I just use hot water in a bucket a squeeze of fairy and a splash of bleach on a sponge,or you could use a non scented antibacterial spray on surface cleaner and wipe it off with a paper towel,I know a lot of people do this.
I don't know about the solution evaporating in the channel,what I do know is these channels get very scungy and lime scaled maybe this prevents that.
Graham.