Getting squirrels to stop chewing the wicker furniture will be difficult. There are a couple of taste repellents that can be used to discourage squirrels. Capsaicin is a readily available repellent made from red peppers. It is usually used to treat birdseed to discourage squirrels from raiding bird feeders. (Capsaicin does not affect birds and is safe to mix with birdseed). Ro-pel is another taste repellent that can be effective at discouraging squirrels. It may be applied to seeds, bulbs, trees, shrubs, fences, siding and outdoor furniture. However, most people find that keeping the furniture inside is the only sure-fire way to protect the furniture. Trapping the squirrels is the other option. Good luck.