I don't know how to convert the numbers on the bag (triple digit) to the one's i'm reading about online.
Maybe hydro would make sense there? Or, grow in straight perlite (a soilless, hydro-like medium)? It seems like people who sell agricultural supplies could explain what those numbers mean. Sometimes it's % of total weight, but it doesn't sound like that. Sometimes % of volume, I've heard.
You might be able to soak, rinse a couple times (if it has nutrients applied too strongly). It wouldn't hurt to try. But, peat needs dolomite lime to maintain a stable ph. The peat I buy has dolomite applied, but I add 1 to 1.5 Tbsp/gal per gallon of peat before I plant. It would be smart to have some, especially if you soaked and rinsed that peat (it might wash away some dolomite goodness.). Finding dolomite might be a problem there too. Lime is confusing. You want something that says it contains 1.2 to 1 calcium carbonate to magnesium carbonate (it breaks down to 1.62 to 1 elemental Ca to Mg.). You want something close to that, not calcium oxide. (You have to be very careful about this or you can kill the plants using the wrong lime.).
Finally, is cannabis legal there? What kind of penalties would you face if caught? (I'm aware of some pretty harsh penalties for fairly minor conduct. I wouldn't want you to be at risk of anything like that.).