Bam by Reckitt Benckiser is a product which I've been seeing advertised, with the usual claims of rapid destruction of grime. I didn't take it too seriously until I helped a friend clean a residential premises from which his tenants had recently departed. He'd heard of Bam and bought some of each of the three types on sale for various tasks. I was amazed to see that the stuff actually worked! Not quite as magically as in the ads, but not with sufficient deviation to make you call the ACCC. (Wikipedia article here) (ACCC site here)
The toilet was a masterpiece of vindictive tenantry. The departed ones had given it their all, short of breaking the bowl. I figure that's on the same principle as a sniper wounding a soldier so that his comrades are burdened with him, rather than killing him outright. If there's no intact toilet bowl, the landlord can't suffer horribly as he cleans it, can he? Yellow-topped Bam thwarted the would-be tormentors' intentions. In a couple of minutes it ripped the plaque-like encrustations from the porcelain (with the help of mild scrubbing). I've had to use a lino knife and scrape fossilised shit off in similar circumstances; in cases where Domestos, Ajax, etc,. were impotent.
The Orange-topped Bam did a great job removing painted graffiti from a set of concrete slabs. These are old, porous and just about impossible to remove contaminants from with normal household products. Industrial-gauge chemicals and high-pressure spraying are usually required. With a bit of help from a scrub-brush, Orange-topped Bam removed all traces of the damage. And it's actually for bathroom and kitchen use! We didn't get around to using the Green-topped Bam so I can't comment on that.
A caveat: I shudder to think of the processes by which this stuff is made, in order to be so effective, and the environmental effects of the ingredients once they go down the gurgler. However, when you're in a tough spot and desperate measures are needed...ya can't be green all the time.
I endorse Yellow Bam and Orange Bam as genuine muck-busters that live up to the claims made by the manufacturers.
(I'm informed by Reckitt Benckiser that the Yellow -topped Bam is now in a new packaging with a white top - Wednesday, 4th June, 2008.)