I’ve been using one very very similar to the one to the original link for over a year now and its still going strong. Its not as powerful as a previous one I had but it certainly gets the job done. You don’t really want a powerful jet for cleaning bikes anyway, I always have the hose set on spray rather than jet.
I also find using a brush to shift the dirt and water to just rinse it off saves massively on water. With a brush 5 litres is more than enough for one muddy bike whereas just using the hose i’d get through 10 litres per bike.
I got mine from Amazon for around £15 added a 10 litre jerry can for water (£5) and a small 12v lead acid battery (£15) and wired up a cigaret lighter socket (£7). Not as slick as a Mobi all in one unit but works pretty good.