BlackHawk...unfortunately, that definitely does not always work...please trust me...don't ask me how I know...just trust me....Even if you have the names of everyone you spoke with.....times....etc.
It's just the world we live in. BTDT
I've done a heck of a lot of international flying. Most of the time, having the spoken requirements prior to showing up for check in has cleared me. And anyone who says something like, "Trust me, don't ask me how I know, but I KNOW" is the first person I disregard.
However, if you still have worries, an earlier check in along with the printed requirements from the Airlines website will do the rest, as mentioned by Meta4.
It really isn't that difficult. Also, having a good attitude instead of a confrontational one will do a traveler a world of good.
If all else fails, have a backup plan. Renting a long term locker is one. Having a family member or friend is another. If someone refuses your checked baggage due to batteries, having a person ready and willing to standby and receive refused baggage is a priority.
Travel smart. Always have a plan in case things go sideways. I would much rather leave my investment in a locker or, with a family member/friend than take the risk, However, if you come with information at the ready and a good attitude, IOW, DON'T be confrontational and instead, be overly respectful, you'll have an experience that succeeds the norm.
I have traveled to Countries whose "security" personnel are only looking for a $20 placed in the right spot to allow you on the plane with the baggage. NOT here in the States, but throughout Central and South America, this is key. Also, many of the lesser Countries in South Africa. Knowing when and where to do so is just as critical as knowing which Countries you can expect to travel with such things. If there is ANY doubt, DO NOT attempt to place such a payment as if your attitude has pissed someone off, you're just as likely to be arrested for trying as for anything else.
In my extensive experience, the individuals attitude plays the largest part in these things. Especially in Hispanic Countries where respect is SO important. Piss off a Cab driver and watch your *** be handed to you by a security agent two weeks later when you attempt to leave the country you've visited.
This isn't rocket science. Yet it can be difficult when people are belligerent in their nature. Personally, in all of my travels, I've never had an issue that simple respect didn't solve.