Hi, I am Dr. Peter and would like to help.
1- How long has it been since he ate the plastic?
2- Do you have hydrogen peroxide?
3- How much does he weigh?
If within the hour you can get some hydrogen peroxide to induce vomiting, give 5 ounces orally. If within 5 minutes he does not vomit repeat it again. Do not give a 3rd time if no vomit. If you can not induce vomiting or the plastic not present in the vomit, feed rice (75%) and boneless chicken (25%) for a day. The idea is so the rice to help him defecate the plastic. If within the next 24-72 hours he becomes lethargic, vomiting or unable to defecate have him checked by a veterinarian, these are symptoms of an obstruction.
If you have additional questions I will be glad to answer them.
Nose being dry as no relevance; just means he is preserving water.
Rice and chicken can do the trick most of the time.