By all accounts, there is no 100% sure guaranteed method. Your fiat bank could go belly up tomorrow and you'd lose all your savings too or maybe the market megacrashes and your stocks plummet or maybe a fire would break out and there goes your silver and whatever you had in paper. (all hypothetical of course)
Bittrex...ugh. They gave me the biggest headache ever before so I feel ya on that mess.
I have seen QRs in some odd places like bottoms of feet and other places in that black light ink. Nobody would know it was there unless - they knew it was there. Might be a killer option!