I have a slipped disc (L5 S1) and have been using disc slip and arnica with ten pads. Also tried disc swelling today. If others have had more/less success with certain settings for same/similar injury?

1. 90kHz to 100kHz using Ultrasound application works very well and it is a medically Proven technique.
http://www.nanovibronix.com/painshield

Egoscue, exercises CAN help some disc issues if not too severe.
http://www.egoscue.com/

Also, PEMF would be excellent too, with TENS be the least effective for "healing". It is used to BLOCK pain only.

High power Pulsed Laser is another good technique. Search Chirpractors using MLS Class 4 Laser
http://www.celasers.com/medical/mls-laser-therapy/why-mls

We also recommend Spine frequencies to you, please check below link for details
http://www.spooky2-mall.com/blog/the-spine-frequencies/

2. I assume your Dr is a chiropractic one, in which case he probably used a "TENS" professional device so unless he used a Spooky2 the settings would be meaningless.

Have you tried "inversion therapy"? Basically one is suspended upside down in an inversion platform which permits the spine to decompress "stretch" allowing nutrients to enter the spinal column and relieving the pressure on the disk. This is a long term protocol.

For more details, please check the link:
http://www.spooky2.com/forums/viewtopic.php?f=18&t=5093