Http-Binding: can a thing-refresh be force-triggered, maybe through openhab's rest api?

Hi,
I’m using the http-binding. I have around 20 things defined, each with 4 to 6 channels. I want the channels to be up-to-date, but the value changes rarely. I have the refresh time setup to be 6 seconds, which ends up generating a lot of requests. In order to reduce the amount of requests, I created an app that detects when the channels need to be updated, and then uses openhab’s rest api to send REFRESH commands to all items affected. However, refreshing an Item does not seem to cause a refresh in the thing. Is there a way, programmatically, to tell the http-binding to refresh a thing?

Thanks,
Edu