Some time back there was a caller who was asking about how to stop a wooden hot tub from leaking. We have a similar tub that has developed the same problem. I can not find any discussion from that caller, but does anyone have any ideas?
Try a couple handfulls of sawdust. It’s a slow process - may take a few days, but the small suction from the leak will gradually pull the sawdust to the leak and plug it. Not a perfect solution but it will definitely slow the leak noticeably.