Well, it's certainly possible to get nice grip running slicks:
https://www.youtube.com/watch?v=v0w5DgMQDv4
I'm not very experienced with slicks, but I know sanding the tires will help. Very shallow tread like those of JConcepts Octagons or ProLine Primes could also work, albeit it might suffer from tread wear.
Then there are traction compounds. It helps for grip, however it has many adverse effects too:
- Using multiple compounds on one track can seriously compromise grip levels;
- Traction compounds are plasticizers, some of which are very nasty chemicals. To avoid health risks, the majority of them should not be handled without gloves and only in a well ventilated area. Additives end up in the carpet, making it very hard to gauge what level of protection you would need during wrenching on your car or marshalling, just to name two examples.
- Tires without compounds/additives applied collect deposits from the track, hampering grip for anyone not willing to use the compounds due to health concerns.
A sanctioned studded tire like Schumacher blocks could perhaps provide a nice alternative. The chunky tread and its lack of sharp features helps to keep consistent performance for a long time.