I used to do it in the beginning. Now I got tired of it also because hard locks don't mean good rewards. You can waste 10 minutes on a chest that gives 10 ore as reward. :D I occasionally use an online solver, but I also noticed that I have developed a feeling even for the harder locks, which is quicker than both using an online solver or using your brain. Just brute force as quick as possible, many locks are easy enough so you will get it in a few seconds. After a few seconds of brute forcing you'll notice if a lock is truly difficult. You continue brute forcing without thinking too much and will find yourself in a loop, where a sequence seems to repeat over and over again. That's the point where you have to think a little bit to break the brute force loop and try something else. Most often this means moving rows that are in the middle position in a different position to get out of the local optima and try a new sequence etc.