there is literally no need to assist or tube feed at this stage , he has only not fed for a few months.
you say you dont have access to mouse pinkies,does that include frozen thawed?? if not then this could be your problem, many snakes will refuse rats but readily take mice.
Also try lowering the heat slightly, my sand boa will refuse food if her temps are above 32c.
i honestly believe that all this moving him about is causing more stress for the little guy and is possibly contributing to the issues. focus on one feeding technique for a couple of weeks at a time and offer food in his enclosure.
Reptiles & Amphibians
1.1.0 Corn snakes- ripley & Sniv.
0.0.1 Jungle carpet python - Vinnie,
0.0.1 cali king snake-cali (mums),
1.0.0 Hognose - Pinnochio
0.1.0 Royal Python - Daenarys
0.1.0 Sand Boa - Dune
1.0.0 Green Bush Ratsnake - Forest
0.1.0 Amazon Tree Boa - Igni
0.1.0 Leopard Gecko - Nyx
0.0.4 Whites Tree Frogs - Gluttony, Ru, Hodor, Pontiff
0.2.0 Siamese cats - Nala and Duchess,