Every now and then I pour a pot of boiling water down my kitchen drains...figure it would melt guck that might be clinging to the side walls of the pipes..also use baking soda and vinegar. That bubbles up and cleans the drains also...
Germs....nothing like a little clorox!! Clean the counters with wipes.
But the big thing is if you have a disposal...let it run with water flowing for 15 seconds after everything is chewed.