Yes, it is possible
Those rules were written with players in mind, but since you are allowed to hire people, using those same rules, you could get them to produce Capital for you.
Earnings: This entry indicates what bonuses the room or team gives to its building’s or organization’s checks made to generate capital. Buildings and organizations act like characters in that they can attempt a check each day to earn capital performing skilled work (without costing you any downtime). You must pay for capital earned in this way as normal.
You would have to use the cost of Laborers though, since hiring that kind of worker is previewed in the rules, not hiring the generic unskilled worker from the hirelings&services rules.
Laborers
Earnings gp or Labor +2
Create 1 Influence, 2 Labor (70 gp); Time 0 days; Size 5 people
This is a one time cost though, instead of a tax on every Capital earned. It may also be reduced in half if you earn that capital instead of paying the full cost.
Also, to clarify on this:
you can spend a day and pay half of the gold normally necessary to buy labor or goods if you do unskilled work.
Maybe it isn't clear, but paying half the Capital cost (10g instead of 20g for Goods, for instance) is called Earning Capital, and that may be done both skilled and unskilled.