Do you have any idea where you made them? You could try using electrum (from electrum.org) but you might need to get a script using bitcoinj if you find they're bip39 nmemonics and not electrum's native phrases (you can use electrum to import bip39 wallets but bitcoinj would be a lot faster imo for the amount of wallets you need to import).

You could also use online tools to convert a nmemonic into an xpub which you can then put into a block explorer. One example of this is https://iancoleman.io/bip39/ but it's risky to use it online. (download a copy of the site and go offline and generate the 1k xpubs if you go that way before coming back online after closing the site)..