Should we therefore encourage cryonics companies to mimic the tactics of scammers so as to make cryonics more popular, so as to make it less expensive for individual people to sign up?

While that may outperform the current approach, it is almost surely not the best of all possible approaches.

Or in other words: maybe instead of donating to SIAI, we should donate to a fund to hire a good PR agency for a cryo corporation.

You won't be revived if everyone is turned into paperclips first.