What home remedy or over the counter medication can i use for loss of voice and a bad dry cough?

Pelargonium sidoides: By far my favorite herbal medicine for bronchitis is pelargonium sidoides, a type of geranium from South Africa proven very effective for bronchitis and colds in numerous research studies. See https://tinyurl.com/y8zkbknv for details. It is sold under the brand name Umcka in the US but of not know how it is marketed in South Africa, but since it is from there should not be hard to find...