Powering on the SSD does nothing. There is no mechanism for passively recharging a NAND flash memory cell. You need to actually read the data, forcing it to go through the SSD's error correction pipeline so it has a chance to notice a correctable error before it degrades into an uncorrectable error. You cannot rely on the drive to be doing background data scrubbing on its own in any predictable pattern, because that's all in the black box of the SSD firmware—your drive might be doing data scrubbing, but you don't know how long you need to let it sit idle before it starts, or how long it takes to finish scrubbing, or even if it will eventually check all the data.