Heli-coil or a solid thread insert (which you would have to retap a bigger hole for) are some options you might wanna consider... The soap idea or any lubricants wouldn't work due to JB Welds strong epoxy mixture... But what you could do is completely fill the hole in flush with JB Weld and let it fully set then drill and retap right into the JB Weld after it's hardened... I've done it on a few other things and they still hold to this day... It's not like a head bolt or exhaust bolt you're dealing with so it will work... Just be careful when drilling and tapping to use an oil like WD-40 to lubricate your work so you dont damage the epoxy... This is all if you dont wanna use Heli-coil or thread inserts which can be a bit pricey because they usually come in a kit with the tap and a few other thread lengths to choose from. | 
