Unctious
merely through transitting through a strong willy willy (aka thermal).
I think you have got your definitions a bit awry. A willy willy (AKA Dust Devil) is not just a "thermal".
A big Willy willy is basically a small tornado without necesarrily having the storm clouds etc over the top of it.
The horizontal components of the wind can be 50 plus knots over a very short distance with sudden wind shear in the opposite direction of equal speed. Crossing through one is not just catching a thermal it's more akin to passing through a horizontal micro-burst.
I have seen them pick up bits of corrugated iron, branches and plenty of dirt/dust and take them up several hundred feet.