Tile Cleaning Chemical Discussion: I have used Groutmaster once and feel like I really didn't get much better results than just using Viper Venom but it seems like in order to get the grout to come out perfect I always end up using some Viper renew to get the grout to "pop" perfectly. I'm super careful when I use Viper Renew (Acid) and mask shit off the best I can but I just have this feeling that one of these days I'm going to damage something if I haven't done so already. My question is, is there chemical out there with the strength of an acidic tile cleaner without the chance of collateral damage from acid? I've tried more dwell time, different grout brushes, my Saturn scrubber, etc... I'm running 2 newer Prochem Apex's, SX-12 and SX-15 spinner. I set the PSI at 1000 with the heat on. What else can I do for better results?