I tried 2 uses.
1- was to make a repair on the back of my headlight wiring (not pretty as first time use! bur it works)
It does not seem to conduct electricity. (thank goodness!)
I took a brittle can cap, drilled it and cracked it all along the bottom.
Made a Sugru blob both sides and let cure for 20 hours.
I then filled the cap with petrol and left it standing for 48 hours
It did not leak - the larger bit on the bottom stayed put- the piece on the inside lifted a bit but not enough to make a leak.
That was probably me not pushing down hard enough to make a good flat seal.
Good stuff . Thanks for the heads up Huan