There is no magic loophole by giving people stuff rather than paying them money directly. In tax law this is just called a non-cash benefit and it is taxable all the same. I'm sure the people writing corruption guidelines had the same insight.

The "loophole" is that, for gifts of more than a token amount, it has to be a legitimate business expense--whoever is picking up the bill. Waiving a conference fee and covering some or all of the travel expenses to a conference, would widely be considered legitimate business expenses. Normally these would be picked up by my company these days if I had a business reason to attend an event and I need to pay for registration and travel. But conference organizers routinely waive at least the conference fees for journalists, analysts, speakers, and possibly others they want to attend.

Working in finance, I have to report any gift above €50. This includes when I would receive a gift or lottery for a training, a conference, etc. So for us it is at least treated like a potential personal payment.