Sorry but I do not understand. Making my Burco overflow as you say surely means the contents go in all directions? Can you please clarify .
This isn't a Burco unless you were to significantly modify it.
Think of something like an old metal watering can, almost, with a collar around the top to collect the wax that comes over the top. This collar isn't just fitted of course, but is an integral part of the structure. It is tilted significantly to cause wax to flow to a discharge spout, on the left in the diagram. The original spout would be where cold water would be run in to lift the wax level.
By all means stick your wax and a brick in the bottom of such a device to take the major crud out. The filter on the top is made of surgical lint. A good head of water into the spout would provide a fair bit of pressure to lift the wax through the filter.
You will have to imagine the slum gum, because in my example I only had very clean wax to work with, of course..
Is it a little clearer now? The technique, not the wax.
Oh, a watering can as mentioned would probably have a bottom that is too thin for the application.
Shame about the Burco, Just use it for making tea . . .
Of course with a Burco, an overflow pipe near the top would probably suffice to take the wax off and is possibly what Heather does, but I don't know for sure.