at some pound shops you can find de-greaser, spray the de-greaser on it and let it soak in for 5 mins then get a bucket of soapy warm water and a toothbrush and give it a good clean then repeat the process until happy then give put oil in a tissue, a tiny bit and roll the chain through it, go for a cycle to work the chain and let the oil get into it then roll clean.
at some pound shops you can find de-greaser, spray the de-greaser on it and let it soak in for 5 mins then get a bucket of soapy warm water and a toothbrush and give it a good clean then repeat the process until happy then give put oil in a tissue, a tiny bit and roll the chain through it, go for a cycle to work the chain and let the oil get into it then roll clean.
worked for me.