What matters is the quality of the domain you're redirecting from. If it's a spammy domain, don't expect much, it's just not worth the risk. I've seen better results when using high-quality, relevant domains with a clean backlink profile, the redirects can still pass some value and improve rankings. It's not a silver bullet, but it can be a useful tactic when done correctly. What's key is to ensure the domain you're redirecting from is closely related to your money site, otherwise, Google will likely ignore it. Clean and relevant domains are the way to go, anything else is just a waste of time.
