The simple solution is to use the cash to buy gold, and store it in the banks safety deposit box. It is then not in the bank other than physically. At least until the regulations get fixed.
1) It’s an all cash business which brings greater security risks, it’s more susceptible to robbery, money laundering and tax evasion. Government authorities cannot easily access transaction data for oversight and cannot ensure safe and legal commerce. And the cash literally reeks of pot so much it’s difficult to re-use. 2) FinCEN, the federal government’s financial crimes cops, have stated that banks may accept legal marijuana businesses but also laid down expectations that are impossible for banks to comply with in a cash business. The banks have no way of knowing if cash being deposited by a marijuana business was obtained legally or not, therefore they are at risk of federal prosecution if they accept cash and it was obtained illegally.