On most of these, you have to push down with a good bit of force while turning counter-clockwise to get past the spring lock, hence the advice to use the heel of your hand. That'* how I do 'em, too. If you wait until it is cold, it is safer, and you can use your bare hand which may be less likely to slip than if you use a rag. Something to improve friction between your clean, dry hand and the clean, dry cap might be nice - like one of those soft (silicone?) rubber cap snafflers used to help remove tight jar lids.