Over the counter pain relivers do not prevent a person from feeling pain. The reduce inflammation and swelling which reduces pain. I still feel pain during practice when there is a reason to feel pain, and have enough sense to know my own limits and limitations. The greatest benefit I get is not during practice but the day or so after it. Interestingly enough the one time I got a significant injury on the mat was during the time period when I had stopped taking the Ibuprofen before class.
Any rate I am not interested in convincing anyone that I am right and they are wrong. What is right for me very well may not be right for someone else.
Train safe.