Waxoyl used to sell a tin of about 3 litres which came with a plunger to pump air in as a mini compressor, it had attached a 'wand' with an adjustable head which is a bit like a weed killer sprayer (now there's an idea). I still added thinners though cos it's a bit thick when cold.
I have not seen it about for a couple of years but try paint refinishers or Halfords ect.
regards
Dave