As above Bob is correct on the hose damage issue
And don't forget OAT = organic ACID technology ! why would you want to introduce acid, however mild into an old cooling system ?
This thread made me check, and I discovered I'd put OAT in my '72. Spent much of last night flushing, and will do the same this evening!
I have an old Honda Goldwing (1978) - that requires a silicate free antifreeze as the silicate apparently destroys parts of the water pump seals.