Yes, I have a trick.
If you just want to check domain availability, you can achieve that with a script that does DNS lookup against the domain names.
From the Unix command line you can use nslookup or dig to get the name servers for a given domain.
If name servers are returned it means the domain is registered.
If no name servers are returned it could mean the domain has no name servers (is inactive), is in redemption, or available.
Or it could be a lookup failure.
Anyway, you only have to double-check those domains.
Thus you have filtered your list.
Multiple lookups can be performed in parallel so it can be quite fast.
Of course it works for any TLD.