So far I have now come up with the following P2SH template:

76a82087637576a91488ac6703b17576a91488ac68

which can be better understood as this:


Noting that:
is the SHA256 hash of the "secret"
is the public key hash for the "reveal secret" redeem script
is the block number for a CLTV refund to occur at and
is the public key hash for the "CLTV refund" redeem script

The lengths of things being pushed onto the stack has been hard-coded in this template which is fine for the hashes but would not be fine if you changed to instead be a timestamp (something I'll be looking into a little later).