Keep one in the shower filled with a mixture of half vinegar and half Dawn dishsoap. Use it to wipe down the shower while you are in there and your shower will always be clean. I keep hearing that this is the magic formula!
The best way to clean and descale your Keurig involves filling the entire reservoir with vinegar and running in through, then letting it set for 4 hours to let the vinegar break down deposits. THEN fill the reservoir with water and run it through.