Decided to take a chance and buy some stuff in bulk from a janitorial supplier…5l shower gel, 5l washing up liquid and a few other bits to make the order up for free p&p. Ridiculously cheap, £6ish delivered for gel and same for washing up stuff, no idea if it is going to be any good but worth a punt.
Think the gel is the stuff supplied to hotels…only found it as I was looking for eco friendly shower gel that comes in environmentally friendly packaging.
Also bought a liter of concentrated soapy stuff for the grandkids bubble guns…tried it out and it works really well. That was £7ish delivered by Amazon, diluted it makes gallons of the stuff. No more tears when those silly little pots the supermarket sell run out in five minutes.