PRUSA likes the bed to be cleaned with isopropyl alcohol. What else should I use? I have the original Prusa i3m3 printer.  Prusa recommends cleaning the bed before each print with isopropanol (isopropyl alcohol), with only occasional cleaning with acetone.  The textured bed prohibits using acetone.

Given the SARS-COV-2 situation and COVID-19, isopropanol is impossible to find, and will not be in stock on shelves in the US for months.

What would you suggest as an alternative that might still be found on store shelves?
Ethanol (Ethyl Alcohol) should work just fine as long as it's around 80% or more. It's very similar to isopropanol as a cleaning solvent. What you're basically doing is removing any stray grease from the bed with a solvent that evaporates quickly. 

Methanol would also probably work. It's very poisonous though, and shouldn't come into contact with your skin, so it requires a bit more careful handling. Methanol also has the benefit that it can't be used for hand sanitizer (since it's absorbed through the skin), so supplies shouldn't run out. 

Look for alternative sources, for example, methanol is often sold as de-icing agent for pneumatic brakes on trucks. Just make sure it's pure alcohol without anything funky added.