Tell me about detergents in Karcher pressure washers

I have just taken delivery of a pressure washer and accidentally read some instructions. Anyway they say that I should only use their detergents as others may damage the machine (but of course they would).

So – anyone use other detergents (for cleaning cars and decking) that aren’t Karcher over-priced branded ones without the world imploding and if so, what would you recommend?

Unless you use something that’s too thick and it damages the pump you will be fine.
Makes no difference whatsoever.
(Or something that’s not designed for that use and it destroys the seals etc)

I have used Fenwick’s caravan cleaner, Halfords own brand, and some stuff from Aldi or Lidl for over a year with no apparent damage.

Ops that probably torn it

That’s what I thought – I couldn’t really see why a product intended for use on car paintwork could conceivably damage a pressure washer.