Podiatry felt is a padding material that is self adhesive designed to be cut into different shapes and stuck on the foot. That means that podiatry felt can be useful to get pressure of bunions in the shoe.
Typically for bunions the felt is cut in the shape of a donut, with a hole in the middle and then stuck on the foot in such away that the padding keeps the shoe from pressing on the bunion. Alternatively the podiatry felt can be cut into the shape of a horseshoe and also adhered to the foot to get pressure off the bunion. Adhesive tape is often used to keep the podiatry felt in place and make it last longer.
Podiatry felt is generally used as a short term measure to get pressure off a bunion from the shoe when other methods can not be used. The big disadvantage of podiatry felt is that it has to be kept on the foot and kept dry (it will soak up the moisture if it becomes wet). This is going to make the method of offloading somewhat unhygienic and necessitate the felt to be replaced every few days which can be a bit inconvenient. It is still a good short term measure until a more medium to longer term measure can be put in place.
The toning or unstable shoes are shoes that are deliberately design to make the muscles work harder and are supposed to give the body an extra workout. These shoes have a checkered history with dubious claims, legal action and settlements with regulatory bodies. Despite that they do have their uses and can be used to change the gait in those with postural problems as the shoes change the gait. They can also be useful for people with a hallux rigidus or a painful osteoarthritis of the big toe joint. The rocker action of the shoes does restrict movement at the big toe joint means that these types of toning shoes can often be prescribed by clinicians for these types of conditions.
So, can they help bunions? Firstly they are shoe of normal width and are not necessarily wide fitting, so they might not be helpful to bunions unless the forefoot of the shoes are wider. If they are not, this may make them uncomfortable to wear. If there is pain in the bunion when walking, especially when the big to joint is extending, then these toning shoes might be helpful as they do restrict that motion. You really need to get the advice of a health professional as to if this is the case in your situation and if these shoes can help.
What if you want to use the toning shoes for reasons other than the bunions? Bunions are no reason not to use these types of shoes. You just need to be careful that they fit correctly in the forefoot and do not cause any discomfort problems in that area. Like anyone using toning shoes, you do need a period of time to get used to them and use them for short periods of time initially. gradually increasing the amount of time that you use them
Yes they do exist and they are popular. Flip flops are supposed to be quite minimalist footwear and not do a lot to the foot. There are however, many different brands of flip flops that are on the market for those who like this type of footwear and do need some sort of arch support. They are often used by those who need foot orthotics or supports which do need good footwear to fit them in, but they do not want to always wear that footwear. The arch supporting flip flops are a good alternative.
A popular brand in Australia is the Archies which are commonly sold in a lot of podiatry clinics. They were designed by a physiotherpist and come in about a dozen different colours. The amount of arch support in these Archies are similar to what you would be in an over-the-counter foot orthotic, so there is no reason to assume that the amount of support that they offer is similar. Some podiatrists have got innovative with them and added some unique modifications to make them more supportive.