I'm not sure if this is any help in degassing but I noticed awhile back, water being drawn up into the vent tube after fermentation with my airlock just hanging there. It appears there's a negative pressure effect due to some cause, perhaps drop in temperature after fermentation or something...
Best thing I ever bought. My intent on buying it was to build oak casks for aging wine, getting the angles true on the staves. I haven't gotten around to those yet but it dang sure works. Have used it to set my drill press, table and compound miter saws.