The problem with cigarette smoke is it gets into all your vent ducting, fixtures and nooks and crannies you cannot get at with a spray bottle and shop vac. The problem with some of these cleaning agents is they can be just as toxic as the smoke residue. You neeed to neutralize the residues left behind by the smoke to protect your health, not just mask them. The best solution is to do something along the same lines as the professional shops. Here is what we did with a BMW we got that almost made me puke the smell was so bad. When we finished there was not a trace of smoke smell, even months later when it would sit in the hot sun with windows closed:
1: Borrow a negative Ion generator and run it in the van for a day. The reason for this is due to not only what the negative ions do, but more importantly, the Ozone that they all generate. Professional shops use Ozone generators. THen put a charger or 12V power supply on your system and run your fans on low to move the ozone through the ducts for as many hours as you can.
2: Next find someone with one of those fountains that make a mist. The mist makers are metal pucks with ceramic discs in them that vibrate ultrasonically and refract the water. Borrow this part from them and then get some peppermint essential oil from the local health food store. Do not get spearmint, etc., because you want the carvones that are present in the peppermint to break down and neutralize the tar residue as much as possible. Place the mist maker in a bowl with about 2 litres of water and 20ml of peppermint oil and run it near the vent intakes with the system on the 'recirculate' setting, again with the fan on low. Go through a couple of bowls and replace the essential oil as necessary. Then do it again on the back seat of the vehicle so the mist can penetrate the seats, headliner, etc. If you can't borrow one, any garden center that sells fountains will have them for about $30.00 and up.
You can also use an ultrasonic humidifier for step #2, but if it has a clear plastic resevoir tank (as most do), the EO will eat the plastic and it will crack, ruining your humidifier.
This is the only real way you can neutralize the cigarette smoke in your vehicle. It may be a hassle, and the Prosolve will still be required to clean your headliner, etc., but if you care about your health it is worth the effort.