In the minds of the idea-people, the guilty party would just walk around/linger....near their push-cart or shopping cart. Then re-camp as night falls.
What I’d suggest is a $20 nuisance-camping fee on public property at 6 PM. You send out 20 nuisance officials (with ample police) to collect the fee each night. You argue or refuse....cops take you for a 96-hour stay in jail (where you get zero access to drugs). People would then vacate the city within a month because of the cost involved.
The only answer at this point: enforce vagrancy laws. Give mandatory 6 month sentences, where homeless are sent to New Deal style CCC camps far away, where their drug and mental problems can be addressed.
Just the threat alone would keep 70% of them off the streets.
Your suggestion just might work, and therefore it will never be used.