Apart from making sure that you have actually got plantar warts rather than a corn- check out the intro to this page here: Plantar warts 101.
Foot warts can be notoriously difficult to treat because they are locked in an area where you can't really get to that easily. So you have to be quite harsh in getting at them.
There are only 3 really main ways that are effective in their treatment:
1- "Mechanical"- this involves reducing with a scalpel or surgical debridement. Obviously needs professional care.
2- "Chemical" - This is where acids, Liquid Nitrogen and Lazer is going to be housed.
3- "Natural"- Over the counter chemicals and other treatments will be here.
There however needs to be some clarification on some of the treatments and the actual treatment of plantar warts as a whole.
1- There is no guarantee, which ever treatment you use, that the plantars wart will go away for good. They can come back. Some people say you can get rid of them easily- you can't. It takes a little work and co-operation from both patient and professional
2- The treatments that a clinician can use can be very time consuming and painful. Some clinicians don't use the right treatment option for the right patient (a nervous patient or child would be better suited to a milder treatment form).
3- You have to be extra careful depending on your medical history of what treatment you can use. Some patients have reduced blood supply and that can cause horrendous problems if not managed properly. Some patients have reduced nerve supply and might not feel the treatments causing the clinician to go further than they should.
4- If you are asked to do something at home, do it. We ran two patients side by side, same treatments. One worked well, the other didn't. It was predominantly because the patient lied about their care at home, and washed off the anti-foot wart medication every night. Strange, but it happens.