This is the great work of doing to escape losses, but it is the same as an investment via fiat. Alos to what point we can wait to enter is the crucial decision. Let us say you enter and again it goes downside, you will still incur losses.
Obviously there is no sure way to avoid loss 100% in trading, even if one holds stable coins like USDT waiting for dump, you might buy the dip and it goes down more, nice point here. And also, to actualize the strategy suggested by OP, one needs a lot of patience and funds too. You can't keep 50% of your funds in USDT if you don't trade with big funds.