You could have a divorce before Jesus died for your sins too. It's just you're no longer going to go to hell for it.
But in one of the books I want to say Paul maybe Ephesians talks about this specific issue and he says that by that measure shouldn't we sin all the more so that Grace can abound all the more, and of course the answer is no.
Ah yes, the Apostle Paul would be such an authority on the matter, a former Pharasee who never met Jesus or his handpicked Apostles who just happened to have a "vision" of Christ pretty much confirming "No, you guys, what I actually meant was this." And managed to hijack the religion to serve the needs of the rich.
12 Designate a place outside the camp where you can go to relieve yourself.
13 As part of your equipment have something to dig with, and when you relieve yourself, dig a hole and cover up your excrement.
14 For the LORD your God moves about in your camp to protect you and to deliver your enemies to you. Your camp must be holy, so that he will not see among you anything indecent and turn away from you.
Only thing that's relevant, and it only a sin if you don't cover it after.
Half of the old testament just feels like health codes. This is make sure to not poop where you live. Other stuff is don't eat foods that will make you sick.
Does flushing it down the toilet qualify? It seems to me that it qualifies. When flushed, excrement is moved to a location (a sewage line or septic tank) that is outside the “camp” (your home), already dug, and already covered, thereby preventing the “camp” from becoming “indecent” (unsanitary). That's the whole reason why sewage systems were invented: it's more convenient and can handle far more excrement than simply burying it in a hole in the backyard.
18 And he said to them, “Then are you also without understanding? Do you not see that whatever goes into a person from outside cannot defile him, 19 since it enters not his heart but his stomach, and is expelled?”[a] (Thus he declared all foods clean.) 20 And he said, “What comes out of a person is what defiles him.