Why not just make your own "waxoyl"?
Here's the recipe for "home brew":
1 pound paraffin wax (use some toilet sealing rings at about $1 each)
2 liters of turpintine or diesel fuel
1 liter of non detergent oil
put the mixture in YOUR crock pot (not the wife's), make small batches, and simmer unitl wax has melted or until the gentle smell of petrolium products alerts the neighbors.
Brush on or use a sprayer. WEAR GOGGLES
Of course a clean vehicle makes this process much more effective. As does having access to a lift, if you have to crawl under there, expect to get extremely dirty.
Really apply it in every nook, allow to drip, as the turpentine evaporates the mixture will thicken and hold.