Controlling Waterfall Auto Updates for Select Rows in Enrichment Processes

Is there a way to turn off the "auto update" feature on a waterfall, but have the entire waterfall sequence run for a given row on command? What I have found is that if I switch off "auto update" in the waterfall, if I run the first enrichment and it come back with no data found, it kills the sequence. The use case here - I'm running an enrichment on mobile phone numbers. I only want to kick off the update sequence for a given row if I need the phone number for that row. Once I have that number, I don't want to re-run the sequence. I also don't want to have it auto run for every row, as it will burn through all my credits. How do I set up the auto updates to ensure that the waterfall only kicks off when I actually want to run it? https://app.clay.com/workspaces/311058/tables/t_mieVhdhQqJze/views/gv_oGK7VfP4xcZZ