how reliable is the pendulum as a method of scrying? I used it during my evocations and gave me good results (answers) but i don’t know how reliable is

The only way to really know is to test it yourself. Since your results may be different than others. Try different methods and keep track of your results.

Since you already use it you should know how reliable it is. If not, start keeping records.

Also EA covers this topic directly and extensively in the Omniscience course.