That's right yup - any standard OTG cable should send the correct signal (really, just shorting a pin to ground) to the micro USB connector on the PCB that tells it to go into USB host mode and provide 5V. Here's a photo demonstrating how you can hook it up (I have a 'charger doctor' just to confirm power is actually coming out, you obviously don't need that in between!)
Note that both USB0 and USB1 can do this, but USB1 is only full speed (12Mbps) versus USB0's high speed (480Mbps) so USB1 isn't really worth it.
I'm hopeful everyone will be able to use the SD slot fine, but it does take a little bit of jiggling the card around. Here's what I do that works 90% of the time:
1) hold the board vertical, so gravity will help pull the SD card down
2) as you insert it, ensure it's running along the metal tab (not underneath it):

3) once it's in position, confirm it's still flush with the metal tab, but also the SD slot/PCB:
If it's not touching the metal tab while you insert it, or it doesn't seem totally flush with the PCB/SD slot curve, it seems to arrive in a position where it doesn't make good contact and the board can't access it. I generally follow the above guide and it usually works, though it's a bit of a pain that you need to be so precise.