Scrubbing Bubbles Mega Shower Foamer

My husband is in the sheet metal industry and comes home covered in metal dust. That mixed with soap leads to a really nasty shower. The metal dust sticks to the shower floor and turns it black. It also gets on the tile and grout. I have tried a lot of cleaners (mostly natural) and have had a hard time making it look very clean even with scrubbing on my hands and knees for over an hour. I know that S. C. Johnson claims to use more earth friendly products, so yesterday I decided to try Scrubbing Bubbles Mega Shower Foamer since he and the kids would be out for the day.
At first I couldn't get the spray to foam, but once I did it started cleaning right away. I saw some of the metal dust begin to run down the wall without any scrubbing. I let the product sit for 3 minutes, as the directions state, and then used a shower brush to scrub the residue. The effort I had to put in was very minimal and the shower is cleaner than it has been in awhile. It even cleared the soap scum off the shower doors. I was very impressed with the results. Unfortunately, I used the entire bottle in one use since it didn't foam right away. I really needed a little more on the floor of the shower, but it still removed most of the black staining.
The fumes from this cleaner were minimal compared to other chemical cleaners. I did not feel over powered by them.
The bottle also states that it will continue to work for four days. I did notice that the floor looked even better after my shower this morning.