Hopefully Franco will chime in here? He's the Australian rep for Tarptent. You might also want to call Henry Shires. Tarptent is famous for its great customer service, and if there's good advice to be had, Henry will provide it! Definitely talk to him before trying any chemical means!

In the meantime, gently peeling the sealant is probably your best bet. At least it's more apt to peel off fairly easily if it was too thick….