You're not the first to have this idea. This is from the wiki:
MEGINGJORO [-1]
Description: Thor's wolf-hide belt. Doubles its wearer's strength.
Musts: You must have an aspect related to your possession of this item.
Skills Affected: Might, Fists, Weapons
Effects:
[-0] It Is What It Is. It's a belt. Pretty stylish.
[-0] Unbreakable. As an Item of Power, this item cannot be broken except with certain powerful magical rituals.
[+1] One-Time Discount. A belt isn't exactly hard to hide.
[-2] Twofold Strength. Megingjoro increases its wearer's strength. As long as the wearer maintains physical contact with Megingjoro, increase that wearer's strength by one step. (Normal strength becomes Inhuman, Inhuman becomes Supernatural, etc.)
and I think the approach shown here is a good one.