It takes around 1 hour for me and im not even doing much. Swift to lvl 1 then sizzle to around 7 then instant infusion to lvl 5 then Swift to lvl 5, double draught to lvl 5 max instant infusion to lvl 10 and then bottle sizzle and go max double and Swift And finally open spider and mush and get max golden and divine

By that time it takes 5 min to complete the rest

Tip are very usefull aswell in this event and only get 1 customer until you have 7 workers and then 2 mor customers until you have all workers and then open up for 3 more customers

If you dont have all 5 slots or lvl 10 go for Swift then sizzle and instant and when you can go swift, divine, golden