Widower Craig Sullivan, who is 49 and originally from North Lanarkshire, set 2,000 bottles adrift last week.
However, his efforts resulted in scorn from some who accused him of littering and polluting the environment.
Mr Sullivan said that his quest had attracted 50 offers of companionship.
He was reported to the Scottish Environment Protection Agency (Sepa) after releasing about 200 of the bottles into the River Cree in Dumfries and Galloway.
Sepa said the bottles had since been removed from the river by locals.