Cheap Garden sprayer for your mud cleaning after track /car cleaning
if you do not want to mod just do manual pumping
Add a tyre valve to the sprayer, i am not sure in Bangkok if the garden sprayer can take 60PSI
do try out your self
just modded the garden sprayer with tyre valve pressure tested tested up to 60 PSI
it can double up for cleaning car, fill up to 60 PSI can enough to drive all 5 litres of water out
I do not take responsibility of pressure higher than 60 PSI