Novel way to bleach tile or big mistake?

A thunderstorm just filled my pool most of the way up the tile. It needs to be shocked as well and it occured to me that I could fill it up above the tile and shock the ba'jesix out of it (20ppm.) My thinking is that it will bleach the grout while I put my feet up and drink beer.

The "Normal" chlorine level of 3ppm has already done a good job of bleaching up to the new fill level.

Can anybody see a good reason why I shouldn't do this? It's supposed to be warm and dry here for several days, that alone will bring it back down to the normal fill level..

k, 20 ppm without an algae problem seems a bit, well... excessive. You are trying to take care of the top 6" of the pool (and if it's just the grout - only a fraction of that area). Adding the extra water will cost you, adding multiple gallons of bleach will cost you, safely dumping 1000 +/- gallons of 20 ppm water will cost you, adjusting the pH and other chems will cost you and having the reagents in your test kit 'bleach out' (so that you don't really know how the water ballance is doing) could cost you BIG time. (Not to mention the oxidation of any metals around the pool, nor the possibility of anyone entering the pool clothed may end up exiting nude ...). ;) Also, if 3ppm does the job, why 'nuke' the pool???
IMHO - getting 1 gal of bleach and a spray bottle would be a preferable option - it's easy enough to figure out how to mix the bleach to get to your 20 ppm level, and apply it where necessary.

Thanks for the reply Waste, I should have posted my numbers. I've got about CYA 50 so 15ppm is the normal shock. (I should have checked the chart before I posted... ;-) I was really only intending to shock it to the Pool Forum Approved numbers and I mistakenly thought it was 20ppm when I posted.

It's not unusual around here to have a storm fill the pool to the tops of the skimmers and I was thinking I would get in the habit of shocking it then to brighten the tile, since I'm already going to have to add chlorine to the rainwater.

I've re-thunk my position and I think I'll just put the beer on the edge of the pool and swim around and use your suggestion of watered down bleach and elbow grease.

I agree with that wholeheartedly, ** except, it may take 2 beers to do the job :D