His name is Kitut Liyur. I didn't know the address (still don't) but we asked at Murnis Warung in Ubud in the hope they'd know. They did, and gave the address to our driver. So maybe other places in Ubud will know of him too.
Nor did we have an appointment, just turned up and hoped he'd be there.
You can buy the offering at Ubud markets.
Didn't tell him why i'd brought my husband to see him, but he worked it out pretty fast.
We loved meeting this old man. I think you will too:)