air-fresheners appealing appearance ball balls color colored colors colour coloured colours contrast deodorant deodorant essences deodorant-ball deodorizer essences fragrance fragrance-ball fragrant freshener fresheners perfumed pot-pourri-alternative scented scented-balls shape shaped shapes surface textured textures bank Bedfordshire England english flow freshen Great Britain green natural nature oxygenate river rural shallow trees water weir flavor flora fresh healthy herb herbal hygiene leaf menthol mint peppermint plant refresh smell spice taste