ACH never really clears, it just hasn't returned yet.
Big banks will have the money next business day at the latest, Tiny correspondent banks in alaska might be as far behind as an extra day or two.
There's a class of return that's supposed to come within 3 days, (NSF/No Account/Closed Account) that's usually what the banks are waiting for, but fraud related returns can be up to 60 calendars later by the rules.