Non lubricated condoms allow personal choice of lubricant, if any, to be used. Also, it allows a taste free choice.
Prior to the invention of latex condoms, condoms were made from animal intestines, essentially the same way sausage casings are made. Latex is better.
Non-latex condoms are not as strong and do not prevent the spread of STDs.
Yes, there are natural lamb intestine, and vinyl. Just read the packages, or ask the Pharmacist[ NOT the clerk ] for help.
No. Sheep skin only prevents pregnancy, the pores in the material allow foreign bodies through that can cause STDs.