How long the recovery takes will depend on how a number of factors including the amount of toxic backlinks and how severe the penalty.
For many websites there may only need to be one disavow request and in other cases there may be several as part of the reconsideration request. In most cases once the first reconsideration request is submitted the website is ready to begin its recovery process and may recover in full. There are no guarantees on how long this will take as we are still at the mercy of Google. However the removal of toxic links is essential to prevent the site losing any further ranking and traffic and is this is the only way to move forward and prevent further negative impact to your site particularly as the algorithm updates may become more targeted and aggressive towards toxic and spammy backlinks.
There may instances where you know you have carried out some spammy backlink practices and you want to find the toxic links and disavow them before Google devalues them and impacts your site, you can contact us to get started on this.