I can’t comment on the drip process but the “leave it at room temperature and drain after ~21 hours” process works fine and makes a delicious (and extremely caffeinated) brew.
I had to stop making it because ten ounces (counting milk and sugar) gave me an anxiety attack and I couldn’t help drinking forty ounces.
Need to try with decaf but it seems wrong somehow.
Anyway. Is a drip method better? I kinda doubt it.