In theory you MIGHT be able to fix it... depending on what you did in the first place. If you worked with all liquid oils or packed the measuring cups if they were soft butters then re-measure each out again and weigh it (weight the container, tare, add the oil to get the weight). Then enter these amounts into your
soap calculator to see how much lye you should have had.
Do the same with the lye - to see ABOUT how much you actually used.
Then you will have to mess around with the soap/
lye calculator to figure out how much oil you need to add. Once you have an idea for that, melt down your lye heavy soap (rebatch it) and add in the oil and cook it till not lye heavy anymore.
But personally I wouldn't. It's risky and it's just gonna end up wasting more materials.
Regarding the tongue test - yea a lot of us do it. But only with soaps we're pretty sure are ok. To do it, you can wet your finger and rub across the surface of a bar of soap or a bit out of your HP batch then put your finger to your tongue. If you feel a bit of zap, like you get if you lick a battery, then it's lye heavy. (I personally just lick the bar, but I'm lazy and I'm not selling the soap). But that's really only a double check. You don't want to actually put raw soap on your tongue - I know cause I've done it!!!