I couldnt imagine growing without some type of device like my liquid transfer pump.... I tried a shop vac when first starting out and omg what a pain... Never again. Search amaz for liquid trasfer pump and you will find it. They are only about $12 and work amazing. The batteries last a long time as well!! Ive only changed them like 3 times in a year.. And i use it everyday.
I like to water with overflow like you do. If I do larger containers this would work great so I don't have to keep lifting the pots over a bucket for the drainage like I do for my 1 gallon pots.
Thanks for the reply. Much appreciated