Read the difference between Denatured Alcohol & Isopropyl on Wikipedia. Isopropyl (91% is best) should be OK. But I would not use Denatured.
I think the best would be 151 proof (75.5% alcohol) rum, available in half-pints & Pints. I have only found Everclear Grain Alcohol (151 proof also) in Liquor stores in large 750ml & Liter bottles. Years ago it was 190 proof, but no longer.