I mentioned 70% iso alchohol since thats what most will have. Be sure you only have a thin small amount- if it looks heavy on contacts or is dripping its too thick . If its too thick do not insert into camera as it may leak onto circuits. You can also use higher grade alchohol if you have it or electronic contact cleaner such as de oxit. I am not responsible if you use too much and damage camera. Hope this helps someone.. The camera is a Canon t6i but should work in other SLR Canons since the card slot is very simular in most. It may also work in other models of cameras but I cannot confirm this as some may have tighter cases/circuity which may not allow alchohol to dry properly so Im not reccomending on other cameras even though it may work.
NOTE:do not use the green isopropl alchohol it has other impurities that might make problem worse. Also try cleaning just the card first then drying if you are unsure if its the camera or the card or try other known good cards. I knew it was camera in my case the card was good. I use this method to clean camera about every 2 years -the Canons seem to have this issue with dirty contacts.