I wouldn't trust ones on ebay unless it's a sealed bottle and still within it's expiration date. Otherwise they'll give you false readings.

The ketosis stix won't help unless you're eating below about 40-50 gm of carb because you won't be low enough to register ketosis.

I found them motivational during induction but I'm not using them much now. Maybe the stall is just a plateau you're at and the weight loss will start again soon.

Squid