[Aircobra101]

tried degreaser, petrol and meth
nothing helps

[Lyonsy]

Try carby cleaner to brake down the varnished petrol but then add metho to keep it from drying out so you can drain/wash out

if its a plastic tank you could also try caustic soda, if its metal i wouldn't recommend it as it could take the gal off and then you get a rust tank

[Aircobra101]

its an LJ rank, not rusty, just covered in that goddam awful gel
i got all the visible bits off with a water blaster, but i think it has baffles at the ends, so can;t get to that
the gal inside looks brand new, so no, don;t want to strip that off

[Lyonsy]

ok some of this then
http://www.bluelionsupplies.com.au/file/1810
their in barry rd bayswater, we got 20L of it to clean up egr parts etc on trucks when they block up etc works well doesent eat plastic ether not sure if they sell it in like 5L containers