The Original Prusa Enclosure has side panels made of PETG. See below some maintenance tips for the sheets.
The PETG sheets in your enclosure can be cleaned by washing with lukewarm water containing a mild soap or a slightly acidic, neutral, or slightly alkaline detergent using a soft clean sponge. Rinse well afterward with clean water and dry with a chamois or a moist cellulose sponge. Subsequent anti-static treatment is recommended.
Fresh paint splashes, grease, smeared glazing compounds, etc. can be removed before drying by rubbing lightly with ethyl alcohol or petroleum ether on a soft cloth followed by a thorough wash and rinse as described above.
Having good electrical insulating properties, the PETG sheets are subject to electric static charge and consequent dust attraction. Treatment with an anti-static agent keeps the sheet free from static charge and dust over prolonged periods.
There are some commercially available products that act at the same time as a cleaning agent and an anti-static agent.
Do not use abrasive or highly alkaline cleaners, acetone, benzene, leaded gasoline, or carbon tetrachloride. Never scrape with razor blades or other sharp instruments.
Remark: Cleaners and solvents generally recommended for use on PC are not necessarily compatible with the UV-protected surface of the PETG sheets.