This is a very nice article that we found from a Plexiglas and acrylic manufacturer. It is completly accurate and we stand behind it as proper directions for the care of your Plexiglas box from us.
curtious of Ridout Plastics. "http://www.ridoutplastics.com/carandclean.html"
"... The Number 1 Problem with acrylic is the use of incorrect cleaners. Yes, we said "cleaners". Please... never, ever, use cleaners containing ammonia. Cleaners such as Windex or 409 will harm your new piece of acrylic. Use only products specifically recommended for cleaning acrylic such as Novus #1, or Brillianize, and a soft cloth. Never use a dry cloth or your hand to clean your acrylic! This rubs the dirt and dust INTO the acrylic as much as it rubs it OFF. First, blow the dust or dirt off, or use water and a soft cloth to float the dirt off. Then use a recommended cleaner to complete the job. Note: a mild solution of dish detergent and warm water takes off stubborn dirt easily without harming the acrylic if you've run out of Novus #1 or Brillianize.
The Number 2 Problem with acrylic is SHOCK. Dropping your acrylic can cause cracking: From large cracks that deal a death blow, to small chips that can turn into mortally wounding cracks. Acrylic is incredibly resilient, but flying off the top of your car was not part of our stress testing. However, cracks in an acrylic sheet can be HALTED by drilling a small (1/8" diameter) hole at the end of the crack. This will keep your sheet in 1 piece while you call us for a replacement.
Scratch Removal: In the event that, after taking meticulous steps to prevent it, your fine piece of acrylic becomes scratched, HAVE NO FEAR. Fine scratches can be removed with a mild abrasive polish such as Novus #2, or Novus #3. Heavier scratches, such that you can feel with your fingernail, will require some elbow effort to remove with a bit of sanding and buffing. A series of grits (150,400,600) followed by a buffing wheel and available buffing compound, will restore the luster of your acrylic! ...."