Scrapebox blasting question

I see all those fiverr gigs where people are offering to blast sites to like 10k-20k sites. I understand that you should not do a big blast like that for your money site, but how does it impact your second tier links? For example, the reason you do not blast your main site is that google would sandbox or deindex your site. So, wouldnt doing a big blast like that on one of your backlink sites hurt the linkjuice it passes? I am a newb and I dont want to blow up my site so if anyone would like to clarify this for me I would greatly appreciate it.