How to unclog a sink drain without harsh chemicals: cup baking soda, cup vinegar, Let it bubble 15 minutes and chase it with a pan of boiling water. Light plunging needed on tough clogs. One pinner claims it "cleared a tough clog in 20 minutes.
Sparkling Castle - for old or dirty grout add 7 cups water, cup baking soda, cup lemon juice, cup vinegar into a spray bottle; Spray onto grout and let sit. Scrub with a brush and mop off excess. Sparkling grout from Sparkling Castle.