1. open js console while standing in the spot you want to spin on
2. make sure the focus is not on the chat window or it won't work
3. Paste this into js dev console:

function simulateKey (keyCode, type, modifiers) {
	var evtName = (typeof(type) === "string") ? "key" + type : "keydown";	
	var modifier = (typeof(modifiers) === "object") ? modifier : {};
	var event = document.createEvent("HTMLEvents");
	event.initEvent(evtName, true, false);
	event.keyCode = keyCode;
	for (var i in modifiers) {
		event[i] = modifiers[i];
	}
	document.dispatchEvent(event);
}
let currentState = 0;

function progress() {
  simulateKey(currentState+37, 'up');
  currentState = (currentState+1)%4;
  simulateKey(currentState+37);
}

4. to start spinning, enter:
let interval = setInterval(progress, 650)

650 is time per spin - 650ms. Note that due to lag lower values are likely to look like random movements elsewhere and only look good for you.

5. To stop spinning, enter
clearInterval(interval)
(to start spinning again, repeat step 4 without the 'let' word)

(it may be a good idea to prepare the stop command in the input field)
alternatively, just restart the tab