Hey Captain Morgan!
(You really should try Goslings.... better rum!)
Vinny chimed in for me when I asked a similar question, only I asked it after the tub had been sitting unused for several months. Like yours, it was due to landscaping work that took longer than expected.
I took as much water out as I could, but did not vac out the plumbing. I also left the cover on through the construction process. Very little dirt got inside.
I filled it, put a cup of dichlor in and ran the jets for two hours, then let it sit 14+ hours. I then put in Swirl-away and let the jets run another hour. The volume of suds was impressive. Don't be concerned!
I then did a drain, refill, dichlor, drain, and refill. The last refill I put in the Metal Gon and Calcium booster and adjusted pH. All seems fine.
You didn't ask about refilling, but thought you might want to know about that, too!
Cheers,
BearBath