pgkevet,
The white fly problem is a big kick in the butt, for they spread all manner of diseases as they sap suck from plant to plant .
That's where the sulphur fumigation helps , some of the deterrent sticks on the surfaces of everything for a long time , not enough to harm humans once the dispersal period is over but plenty enough to snuff out white flies & their eggs .
Two years ago I used Jeyes fluid & a drop of fairy liquid as the concrete floor scrub for my glasshouse.. over both winters the floor grew a green skin of crud that produced 10 mm dia bubbles of some sort of gas .
This March after drying out the place I used a strong solution of cheap sodium hypochlorite bleach and a couple of drops of dish drops to coarse spray all the internal glass & ally frame , as well as putting a couple of buckets of it on the now dried & swept concrete floor ..
After returning to it a day later rewetting it with more solution and giving it a good rub in I hosed it off . Once the floor had drained off via the floor drain I gave the floor another spray of clean bleached water.
So far there is not a trace of anything growing on the damp floor ( I have auto misting & sprinklers to each pots /tub ) nor do I have any great number of pests attacking my capsicums ,aubergines , tomatoes or potted seedlings such as peas lettuce, herbs , brassicas etc.