Nope. Using Dig is the only way.
If you've already used the TM, try getting a Pokemon that learns Dig on its own, like Diglett.
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Get relicanth and wailord. Put relicanth in the first slot and the wailord in the last. Then make a pokemon who has dig use dig.
In second room in Sealed Chamber, make your party pokemon, Wailord first, and last in Relicanth. Then, read the braille.
You may have been in; but may not have been through the Braille challenges. When you dive, the first Braille says; Dive here, so you dive and you come up in the sealed chamber. The first Braille inside the chamber says: Dig here, so you dig and the door opens; revealing the next part of the chamber The second, and final Braille says: First comes WAILORD and last comes RELICANTH. This first guy got it mixed up. Three doors open. If you meant you cant get inside the door to Regice, according to my memory, you run around the walls of the cave with no collisions.
You need Relicanth to be first in your party, and A wailord as the last, and then when you've read the braille you need to get one of your Pokemon to learn dig.
If you mean Aron, it learns Dig by using the TM28. If you mean, Aggron, it can also learn Dig by using the TM28. They both cannot learn Dig naturally by leveling up.