I’ve always found it works far better on road grime and wheels with rim brakes than on ‘mud’ – as you say you just hose the mud off, whereas road grime needs to be ‘lifted’ a bit before it’ll rinse.
It’s no use on thick mud which a simple hose/brush shifts, it’s a surfactant that is good at removing stubborn stuff that’s stuck to the surface of the bike (especially brakepad grime).
So for a proper minging bike I want back to spangly new looking
1) hose off the “macro” mud and crud
2) spray with muc off
3) make a brew whilst it’s soaking
4) wash with bucket/brushes/sponge/cheap car shampoo
5) rinse with hose
(6) GT85/WD40 chain and mech(s) to prevent rusting, or even wipe it down with a microfibre cloth if it’s not going to be used for a while)
I also use it on my motorbikes to shift dried on dead bugsplats etc. Actually, I use Fenwicks FS1 diluted as it’s far cheaper.
I’ve got an unused bottle that my son was given for Christmas. Might try using it in the bucket of hot water to see if it gets wheel rims cleaner than car shampoo
you don’t put it in water like shampoo, you spray it on first. Works really well cleaning alloy wheels up.