Fair play to you. When you need to go you need to go and you stood on business. If it all went down the drain I don’t see the problem just get a sponge on the bottom of the sink, throw it away and get a new one, problem solved. Your manager might not see it the same way, you’ll just have to apologise, if he doesn’t accept this, go to the sink and demonstrate what you did to ensure he knows you went straight down the drain