Does this really works? Any benefits? How and when should I drink this?
Depending on your area, application of lime shoud be done in mid to late autumn as a top application to the soil.
I don't know how much lime it was, or how acidic you soil is, but I'd topdress it with some garden sulfur or acid plant food like Mir-Acid and water it in to neutralize the lime and acidify the soil.
DO NOT put lime anywhere near your Rhody's unless your soil pH is above 7, they will simply die.They require an acid rich soil, ideally between pH 4.5 - 6. Get you soil tested first, you can buy testers cheaply from garden centres. Rhody's and lime do no mix, they are like chalk and cheese and you may be giving your shrubs a death sentence. Most house and garden plants that die, have been killed by kindness.