How does this work in a homeschool co-op?

Well, and better than it works alone, because the thing this material is missing on its own is other kids doing the same thing in the same week.

The natural shape is that the reading and the workbook happen at home, and the co-op session is for the parts that need other people. That split matters, because co-op time spent watching kids fill in workbooks is a waste of the one thing a co-op has that a kitchen table does not.

What the group time is actually for:

Practicing the ask. Kids saying their price out loud to somebody who is not their parent. This is the hardest part of the whole program and it gets dramatically easier with an audience that is in the same position.

Reporting numbers. Each kid says how many people they asked, how many said yes, and what they made. Nothing motivates a twelve year old like another twelve year old having asked seven people.

Rejection practice. Role play the door that closes mid-sentence. Much easier to rehearse in a group, and it turns the worst part into something faintly funny.

The week five conversation. Every kid hits the point where it stops being fun, and hearing four other kids say they wanted to quit too does something no adult can do.

Mixed ages work fine here and often better. Older kids explaining what they tried is worth more than an adult explaining it, and the younger ones get a realistic picture of what is possible.

One structural thing: kids should run different businesses. Eight kids all starting lawn care in the same town creates competition inside the group, which sours quickly. Steering them toward different ideas early avoids it entirely.

Each kid needs their own workbook and consumables. Those get written in and used up.