A natural alternative
If you’d rather not use the petroleum jelly, a mixture of beeswax, olive oil and coconut oil is a great, natural alternative. You can make this by combining eight tablespoons of olive oil and eight of coconut oil in a pan on a low heat. Then add the comfrey as directed in step 2. Once the mixture has been strained, return to the pan on a low heat and melt in four tablespoons of beeswax pellets. When all melted, you can pour the liquid into a clean jar as directed in step 4.