For example
I've already tried putting a towel in between the paper with dry seal and flat iron, it makes the job done but Im still looking for easier way
If you have to get rid of the dry seal, you have to do it that way.
You have to shorten the structure in the paper again. The seal lenghtend the paper structure.
Using abrasive you can get rid of the seal on one side, but you are then under the smooth paper surface. You are in the structure inside. So mostly you see it.
On the other side the seal is still there.
If a copy of the document will do, then either
or
HACK: Reverse the process.
The dry seal design "in relief" that you see is the result of embossing (pushing up) the paper. (Flip the paper over and you will see the opposite—ridges 'become' valleys.)
The dry seal is formed by squeezing the page between a deeply engraved surface and another layer made from a mold of the engraving. The result is what you see.
What you are about to do is "burnish" (rub and press) the paper flat again. You'll squeeze the page between a flat, smooth surface and a "burnisher" made from a teaspoon.
The action is similar to squeezing dough between a counter top and a rolling pin to thinify it.
Good luck.
Try with sandpaper.
Buy sandpaper with grit around 400, and try gently to remove the seal. If you notice it tears the paper, stop of course.
I didn't try it myself, but sounds like it might work.