Karcher - Which Detergent??

[nomad_fr]

Finally got round to getting myself a karcher and will be giving the FR a much needed clean!
What detergent can be used - the manual of course says to just use karcher products (of course) but surely something else can be used>

It is the type with the pick up tube - therefore I am guessing I need to mix with water? what mix is required?
thx

 

[TubbyTwo]

any car shampoo will work mate, i usually have around an inch in the bottle and top it up with water, foams up well.

Nothing like a snow foam attachment but still works ok.

 

[millsyscossie]

Auto Glym preassure wash

Think halfords have a 5ltr tub for £12 thereabouts

 

[Feel]

My mate repairs them, and swears blind that you can tell the difference when you look inside.

The one I have gets knackered (pressure switch) whether I use Karcher stuff or not

Edit: I mean, even if I religiously stick to Karcher only, it will eventually lock up anyway.