1. Not cleaning the bike, idea is that dirt is not pushed into places it’s not supposed to. I guess mud contains the moisture for longer allowing corrosion to take place. (my previous preferred method, along with various fenders)
2. Blasting the bike with a hose/pressure washer and allowing to dry in a warm place. Hopefully clears away mud etc, but can get forced into bearings. (a method I don’t intend to try)
3. Cleaning gently with muc-off etc and a light hose, then treating all vulnerable areas to a water disperser/non stick coating (which seems like a good idea to me at the moment). Idea is that water/muck never gets a chance to penetrate, but chemical can destroy grease, but a grinding paste situation shouldn’t happen.

Whats your preferred treatment?

Rigid singlespeeds.

make sure they’re properly greased in the first place.

don’t jet-wash, but other stuff does need cleaning, so use a bucket and soft brush.

strip and rebuild before they need it.

Rigid singlespeeds.

Lol, how very STW

Excessive cleaning/hosing of any bearings will get crud in them but it will get in anyway so you need to maintain them. Pop the seals off and fill them with waterproof marine grease (search “Morris K99” on ebay) and also put a layer of grease on the outside of the bearing to catch the crud before it gets in the bearing but this will need cleaning and replacing regularly otherwise it will be counter productive. When they are knackered replace them with good quality bearings which have much better seals (e.g SKF, INA, FAG, EZO etc)

I pretty much leave them alone. My bikes don’t really get washed unless they’re really hanging, better to let them dry then brush off (or ride off ;)) Best option? No idea but I complain a lot less about bearings than a lot of people do.

Mudflap on the downtube stops a lot of filth being sprayed onto mine, the bearings definitely last longer than they used to before I fitted it.

Grease the bearings before installation