What about using URL shorteners for link building?

Now that Google let it clear link building, if not natural, drives to a penalization/banning, what about submitting sites to directories, links exchange, blog commenting using a mix of money site url, url shortener and free subdomain services?

I understand third services make link juice less effective, but is better than a penalization, isn't it?

So you're thinking that the link juice would be passed through the url shortener and then on to your site? If so, I would imagine that penalties would do the same.

You can check those with second tiers rather than main tier to safeguard the site.

Typically these services are a redirect so they really would not offer any protection from a penalty. Directories certainly are not a risk free or even an effective source of links since Google continues to remove them from their index. Reciprocal linking or link exchanges, have not been effective for years and are also considered manipulative in Google's eyes. Same with blog comments for the most part.

If you are going to experiment for yourself, definitely to not link directly to your money site.